NSU Motorenwerke AG, or NSU, was a German manufacturer of automobiles, motorcycles and pedal cycles, founded in 1873. Acquired by Volkswagen Group in 1969, VW merged NSU with Auto Union, creating Audi NSU Auto Union AG, ultimately Audi. The name NSU originated as an abbreviation of "Neckarsulm", the city where NSU was located.[1]

NSU originated as the "Mechanische Werkstätte zur Herstellung von Strickmaschinen",[2] a knitting machine manufacturer established in 1873 by Christian Schmidt, a technically astute entrepreneur, in the town of Riedlingen on the Danube.[3] The business relocated in 1880 to Neckarsulm.[3] There followed a period of rapid growth and in 1886, the company began to produce bicycles, the first of them a 'high wheeler' or 'Penny-farthing' branded as the "Germania".[4] By 1892, bicycle manufacturing had completely replaced knitting machine production. At about this time, the name NSU appeared as a brand name.

The first NSU motorcycle appeared in 1901,[5] followed by the first NSU car in 1905.

In 1932, under pressure from their bank (Dresdner Bank), NSU recognised the failure of their attempt to break into volume automobile production, and their recently built car factory in Heilbronn was sold to Fiat,[6] who used the plant to assemble Fiat models for the German market. From 1957, NSU-Fiat cars assumed the brand name Neckar.

In December 1946, Das Auto reported the company had resumed the manufacture of bicycles and motor-bicycles at Neckarsulm.[8] For Germany, this was a time of new beginnings, and in July 1946, a new board was appointed, headed by General Director Walter Egon Niegtsch, who earlier in his career had spent 17 years with Opel.[8]

NSU motorbike production restarted, in a completely destroyed plant, with prewar designs like the Quick, OSL, and Konsul motorbikes; furthermore, the HK101 continued to be sold by NSU as an all-terrain vehicle in a civilian version. The first postwar model was the NSU Fox in 1949, available in 2-stroke and 4-stroke versions. In 1953, the NSU Max followed, a 250 cc motorbike with a unique overhead camdrive driven by reciprocating rods. All these new models had an innovative monocoque frame of pressed steel and a central rear suspension unit. Albert Roder, the chief engineer behind the success story, made it possible that in 1955, NSU became the biggest motorcycle producer in the world. NSU also holds four world records for speed: 1951, 1953, 1954, and 1955. In August 1956, Wilhelm Herz at the Bonneville Salt Flats, Utah, became the first man to ride a motorcycle faster than 200 mph (322 km/h).

In 1957, NSU re-entered the car market with the new Prinz (Prince), a small car with a doubled NSU Max engine, an air-cooled two-cylinder engine of 600 cc (37 cu in) and 20 hp (15 kW). Motorbike production continued until 1968. NSU's last production motorcycle was the Quick 50.[9][10]

In 1964, NSU offered the world's first Wankel engined car: the Wankelspider. In development of the project, NSU built the Sport Prinz, with a 129 hp (96 kW) 995 cc (60.7 cu in) 2-rotor.[11] In the same year Prinz 1000 and derivatives like the TT and TT/S followed. The Typ 110 (later called 1200SC) was launched in 1965 as a family car with a more spacious body design. The last NSU cars with a conventional four-stroke engine had the air-cooled OHC four-cylinder engine in common. The car was marketed in the U.K. as "NSU TYP 110", and Karobes, a major supplier of car accessories, provided a head rest specially for this car: "A new one which can be fitted without a screw, and may be adjusted forwards and backwards."[12]

In 1967, the four-door NSU Ro 80, with a 115 hp (86 kW) version of the same 2-rotor,[11] was presented to the public. Weighing 1,200 kg (2,600 lb), it had a Cd of 0.36, disc brakes, independent suspension, and front wheel drive by Fichtel & SachsSaxomatic three-speed transmission.[11] It soon gained several design awards such as "car of the year 1967", while drivers liked its performance.[11] Virtually all the world's major motor manufacturers purchased licenses from NSU to develop and produce the rotary engine, with the notable exception of BMW.[13]

Despite its public acclaim, sales of the Ro 80 were disappointing. The transmission drew complaints and the engine suffered numerous failures even at low mileage.[11] Competitor automakers, apart from Mazda, held back from taking a lead in developing and marketing the Wankel technology, and anticipated income associated with those royalty deals failed to materialize.

The development of the rotary engine was very cost-intensive for the small company. Problems with the apex seals of the engine rotor significantly damaged the brand's reputation amongst consumers. In 1969, the company was taken over by Volkswagenwerk AG, which merged NSU with Auto Union, the owners of the Audi brand which Volkswagen had acquired five years earlier. The new company was called Audi NSU Auto Union AG and represented the effective end of the NSU marque with all future production to bear the Audi badge (although retaining the four interlocking circles of Auto Union). The management of the new combine was initially based at the Neckarsulm plant, however when the small rear-engined NSU models (Prinz 4, 1000, 1200) were phased out in 1973, the Ro 80 was the last car still in production carrying the NSU badge. Audi never made use of the brand name NSU again after April 1977, when the last Ro 80 was sold.[11] In 1985, the company name was shortened to Audi AG and management moved back to Audi's headquarters in Ingolstadt.

Even as production of the Ro 80 continued in the Neckarsulm plant, production of larger Audi models like 100 and 200 was started. The Porsche 924 and later Porsche 944 were also assembled at Neckarsulm. Those models were joint venture projects of Porsche and VW, but Porsche did not have the internal capacity to build the 924 and 944. Currently, Neckarsulm is the production plant for Audi's topline vehicles like A6, A8, and R8. It is also the home of the "Aluminium- und Leichtbauzentrum" where Audi's aluminium-made space frame bodies are designed and engineered.

NSU is primarily remembered today as the first licensee and one of only four automobile companies to produce cars for sale with rotary Wankel engines. NSU invented the principle of the modern Wankel engine with an inner rotor. The NSU Ro 80 was the second mass-produced two-rotor Wankel-powered vehicle after the Mazda Cosmo. In 1967, NSU and Citroën set up a common company, Comotor, to build engines for Citroën and other car makers. Norton made motorcycles using Wankel engines. AvtoVaz (Lada) manufactured single and twin rotored Wankel powered cars in the early 1980s. Only Mazda has continued developing the Wankel engine and made several more cars with the Wankel engine.
NSU developed their last car in a recognised conventional layout, (front engine front wheel drive, water cooled) -this was the NSU K70, Volkswagen adopted as their first water cooled front engined car the VW K70. The first VW golf cars used the NSU K70 engine and is almost identical. Subsequent VW models share no lineage and are descended from Auto-Union designs.

Mike Hailwood raced in 1958 on Ducati, NSU, MV Agusta, Norton, Triumph, Paton and in 1958 4th in the world championship 250cc (NSU) 5. John Surtees[15] enters the season 1955. That year, he signs his first podiums on a Norton in 350cc in Germany and Ulster which he also won the round in 250cc while signing the best lap in the race for his only appearance on the handlebars of a NSU John Surtees remains the only champion of the world motorcycle and of Formula 1.

The first NSU cars were the single cylinder 3-wheeled Sulmobil, first produced in 1905. At the same time NSU produced the NSU-Pipe 34 PS and NSU-Pipe 50 PS under licence from the Belgian firm of Pipe. Two further Pipe models were to follow, and a range of NSU-specific 3- and 4-wheeled models.

The NSU Prinz was also built in Yugoslavia (by PRETIS), Argentina (by Autoar) and Egypt, under licence.

In Uruguay, the Prinz 4 was built by Nordex S.A., and a new model, the P6, combined the engine and mechanics of the NSU model with a separate body completely redesigned by Carlos Sotomayor. From 1970, the P10 was built as the successor model to the NSU P6. This had the larger engine of the NSU Prince 1000 and a 21 cm extended wheelbase.

The first "Neckarsulmer Motorrad" motorcycle was produced in 1901, using a Swiss 1 3/4 hp Zedel single-cylinder AIV (automatic inlet valve) motor with battery/coil ignition, clamped at the underside of a heavy-duty bicycle frame (of NSU manufacture), with the crankcase slightly below and in front of the pedal crank. Specialized racing motorcycles were campaigned from 1905 in events in Europe, the UK, and USA. In 1907, British manager Martin Geiger rode an NSU in the inaugural Isle of Man TT, placing fifth.[23] NSU had several successes in the Isle of ManTT races in the 1950s. In 1908, an NSU v-twin took part in the Ormonde-Daytona beach speed record races for cars and motorcycles, ridden by Eugene Gaestral, who returned with an improved machine the following year.

During the 1930s, and in the mid-1950s, NSU was the largest motorcycle producer of the world, in its peak year (1955) producing 350,000 machines.[24] NSU holds four world records for speed: 1951, 1953, 1954 and 1955. In 1956, NSU brought a team of six motorcycles of different engine capacities to Bonneville, Utah, to set World Land Speed Records. They had success in all categories, and most notably raised the absolute motorcycle speed record to 211 mph, with Wilhelm Herz piloting the Delphin III, a fully streamlined motorcycle with a 500cc supercharged DOHC twin-cylinder Rennsport engine.[25] This machine still exists, in the Audi Museum in Stuttgart, Germany.

The NSU Quickly was the most popular moped of its time.[citation needed] It was produced between 1953 and 1966 in over 1,000,000 examples and still can be found today all over the world as more than 60% were exported.

NSU was the principal maker of the Kettenkrad halftracked motorcycle (1940–1949)
The Sd.Kfz. 2 was designed and built by NSU Motorenwerke AG in Neckarsulm, Germany. Designed and patented in June 1939, it was used for the first time during the invasion of the Soviet UnionOperation Barbarossa in 1941.